a) Field of the Disclosure
This application relates to the field of lightweight cabin, cockpit, and storage window and door seals for commercial, personal, military, and other aircraft.
b) Background Art
Malleable seals for aircraft have been in use since aircraft first used windows. Such seals are similar in some respects to the malleable seals found in homes, automobiles, boats, and elsewhere. Generally, such seals form a weather-tight malleable separation between the outer hull (frame and skin) of the aircraft and the window(s). Such seals are utilized so that the interior of the cabin stays warm, dry, and in modern aircraft, pressurized. Such seals must remain useable in the presence of very high pressures differentials between the interior and exterior of aircraft that fly at high altitudes. Such pressures are utilized to supply sufficient oxygen (and heat) to passengers and crew.
FIG. 1 shows a highly schematic view of a modern aircraft window assembly 20 in cross section. The aircraft skin and frame are shown at 22 with an outer transparent window pane 24 and inner transparent window pane 26 separated by an airspace 28. The use of double panes is a common structure which improves thermal and acoustic insulation of the assembly, and in some applications allows for air to be evacuated from the airspace 28 to reduce condensation, improve thermal and acoustic insulation, and improve visual transmission through the window assembly.
Especially as fuel costs rise, aircraft manufacturers and airlines are looking to reduce the weight of the aircraft and load in any way possible. Airlines have in some applications removed magazine racks, redesigned food and beverage carts, used lighter frame materials such as carbon fiber over the much heavier traditional aluminum, reduced the allowed baggage each passenger is allowed to bring without additional cost to them, etc.
As the limits of weight reduction infringe on safety issues, reducing the weight of the aircraft and load becomes exponentially more difficult.